TUESDAY, April 13, 2021 (HealthDay News) -- After six people who received the Johnson & Johnson one-dose COVID-19 vaccine developed a type of rare and severe blood clot, the U.S. Food and Drug Administration and the Centers for Disease Control and Prevention on Tuesday each said they will seek a "pause" in use of the shots as they review the data.
The six cases involved a cerebral venous sinus thrombosis and developed among women between the ages of 18 and 48 years; symptoms occurred six to 13 days after vaccination. According to The New York Times, in one case, a woman died and a second woman in Nebraska is in the hospital in critical condition.
The agency officials stressed the rarity of the cases: More than 6.8 million doses of the Johnson & Johnson vaccine have so far been put into Americans' arms, their statement noted. Still, out of "an abundance of caution," the CDC is convening a meeting of its Advisory Committee on Immunization Practices (ACIP) on Wednesday to "further review these cases and assess their potential significance," the statement said. Experts at the FDA will then review the ACIP findings.
Such cases have not been reported in the two other vaccines being delivered to Americans, two-dose shots from Pfizer-BioNTech and Moderna. According to The Times, more than 23 million doses per week of those shots are now being distributed across the United States.
In a statement, Johnson & Johnson said that "we are aware that thromboembolic events, including those with thrombocytopenia, have been reported with COVID-19 vaccines," The Times reported, and "at present, no clear causal relationship has been established between these rare events and the Janssen COVID-19 vaccine." Janssen is the name of the division of Johnson & Johnson that developed the vaccine.
The news came as another blow to vaccination efforts worldwide. In Europe, concerns have been raised over the AstraZeneca COVID-19 vaccine, after 222 similar cases of clotting occurred, out of the 34 million shots administered to people in Britain and the European Union, The Times noted. The AstraZeneca vaccine is not being used in the United States.